Jan. 31, 1916 
Effects of Refrigeration on Trichinella spiralis 
843 
clear, spherical bodies, seemingly of a vesicular nature. The gonad (ovary 
or testis) forms a continuous mass of cells closely pressed together, 
intercellular divisions and nuclei being indistinct in the living specimen. 
The body cavity forms a thin but distinct space between the internal 
organs and the parietal wall. In short, the normal living trichina larva 
freed from its capsule by artificial digestion presents a sharp clear-cut 
bright appearance which is quite characteristic but difficult to describe. 
The changes shown by the trichinae from artificially digested meat in 
experiments 118, 106, and 94 are typical of those produced by the expo¬ 
sure of trichinous meat to various low temperatures. In these instances 
the temperatures were 13.5 0 to 15 0 , 10.5 0 to 13 0 , and 5 0 to 6.5° F., 
respectively, and the period of exposure 14 days in each case. The meat 
was all of the same origin—i. e., from six hogs, mixed together, portions 
of about half a pound being inclosed in tin cans and placed in freezers 
maintained at the temperatures stated. The cans were removed at the 
end of 14 days and the meat allowed to thaw at ordinary temperatures. 
Two days after removal from the freezers the meat from each can was 
ground up, digested overnight in an artificial gastric juice, washed and 
sedimented in a 0.6 per cent salt solution and the trichinae thus obtained 
subjected to examination. As usual, for the purpose of controlling the 
results of these processes upon the frozen meat, unfrozen meat from the 
same carcasses was digested, washed, and examined in exactly the same 
manner. 
Out of 95 trichinae from the meat which had been exposed to a tempera¬ 
ture of 13.5 0 to 15 0 F. (No. 118), only one was inactive, this one being 
pale in color, and the nuclei in the cellular body having a solidified appear¬ 
ance. The 94 others were more or less tightly coiled when cold, and most 
of them were quite lively when warmed. The granulation of the proto¬ 
plasm of the cellular body differed only slightly from normal, and its color 
was nearly normal; the nuclei showed commonly a small central point of 
more solid appearance than the remainder of the nucleus. The gonad 
either showed only slight changes from normal or the germ cells were 
rounded instead of being closely pressed together, this rounding of the 
cells occurring in only a part of or throughout the gonad. Two of the 
test rats in this experiment became heavily infested; one was negative; 
one showed 9 trichinae in the diaphragm; and one 3 trichinae in the 
diaphragm. 
Fifty trichinae were examined from the meat which had been exposed 
to a temperature of 10.5 0 to 13 0 F. Of these, five were inactive, pale in 
color, their coils expanded so that they resembled a figure 6, and the nuclei 
of the cellular body of the esophagus were solidified. The 45 which were 
active were more or less tightly coiled when cold, some of them being 
quite lively when warmed. The color of the cellular body was rather 
paler than normal, the protoplasm abnormally granular, the nuclei either 
not apparent or exhibiting a solidified central portion. The cells of the 
